/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */
package org.apache.iotdb.lsm.wal;

import java.io.FileNotFoundException;
import java.io.IOException;

/**
 * get records in wal file
 */
public interface IWALReader {

    /**
     * close resource
     *
     * @throws IOException
     */
    void close() throws IOException;

    /**
     * determine if there is a next record
     *
     * @return returns true if there is, else returns false
     * @throws FileNotFoundException
     */
    boolean hasNext() throws FileNotFoundException;

    /**
     * return the next record
     *
     * @throws FileNotFoundException
     */
    IWALRecord next() throws FileNotFoundException;
}
